# coding=utf-8
import pygame
from bullet import Bullet

class Ship():
    def __init__(self, ai_setting, screen):
        """初始化飞船并设置初始位置"""
        self.screen = screen
        self.ai_setting = ai_setting

        # 加载飞船图像并且获取其外接矩形
        self.image = pygame.image.load('images/ship.bmp')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        # 飞船放在屏幕底部中央
        # 可设置相应 rect 对象的属性 center 、 centerx 或 centery
        # 要让游戏元素与屏幕边缘对齐，可使用属性 top 、 bottom 、 left 或 right
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        self.center = float(self.rect.centerx)

        self.moving_right = False
        self.moving_left = False

    def fire_bullet(self, screen, bullets):
        new_bullet = Bullet(self.ai_setting, screen, self)
        bullets.add(new_bullet)

    def update(self):
        if self.moving_right and self.rect.right < self.screen_rect.right:
            self.center += self.ai_setting.ship_speed
        if self.moving_left and self.rect.left > 0:
            self.center -= self.ai_setting.ship_speed

        self.rect.centerx = self.center

    def blitme(self):
        # 在指定位置绘制飞船
        self.screen.blit(self.image, self.rect)
